Obviously this manga was created to sell toys. It does a poor job even at that. It's understandable that it was canceled. It's very short, so I'll do a pros and cons list instead of an element breakdown.
-I like the character designs, they're fun and quirky for the most part and lend themselves to a range of tones and angles.
-I like the art... in places. There are a few rare moments where an angle looks really good. Even if most of the time it's average and sparse.
-It is very hard to tell what's going on. I suspect if I knew how to use the
toy I'd understand it better, but as it stands I still have no idea how the game they're playing works, this makes understanding the story comparable to playing a video game where the only description of anything is through useless flavour text.
-The actual characters have no personality beyond "I like this game". It makes it very boring to read, even as a kid I would have dumped this.
-Also the 'training' takes like an hour. This makes the defeating of the bad guy have very little weight. I was kinda led to the idea that it wasn't needed.
Overall this manga is mercifully short. Boring, inspired kids fodder designed only to get people to buy a toy. I don't want to sound malicious though, it is mostly harmless. But I would give it a miss if I were you.